No hit results from 3D models with no material in Feb CTP

In Dec CTP I was using a 3D sphere with no Material (Material = null) as a
trackball for my scene. I have ported the code to Feb CTP and it seems that
the sphere is not hit anymore.
I just wanted to ask if this is a voluntary change and if it is the intended
behaviour in the final version WPF and I should implement another trackball
(probably the one from Daniel Lehenbauer).

--
Valentin Iliescu [MVP C#]

Hi!

My 3D objects disapeared after upgrading because the UserControl no longer
streches its content.
So you might assign a material to find out... That is the nice part about
your implementation.

BTW: Although your implementation is very creative I'd reccomend against it
because of performance. Just calculating a Quaternion from two
screencoordinates is much faster than doing a hit test.

Erno
----
WPF tutorials: http://blogs.infosupport.com/ernow/articles/1878.aspx



"viliescu" <viliescu@discussions.microsoft.com> wrote in message
news:38440214-4892-4DAB-99B3-E270594B0F16@microsoft.com...
> In Dec CTP I was using a 3D sphere with no Material (Material = null) as a
> trackball for my scene. I have ported the code to Feb CTP and it seems
> that
> the sphere is not hit anymore.
> I just wanted to ask if this is a voluntary change and if it is the
> intended
> behaviour in the final version WPF and I should implement another
> trackball
> (probably the one from Daniel Lehenbauer).
>
> --
> Valentin Iliescu [MVP C#]

Thanks Erno, I have tried to add a transparent material and/or set the
opacity to 0 but it's not working - the objects from the sphere interior are
not visible anymore.
--
Valentin Iliescu [MVP C#]


"Erno" wrote:

> Hi!
>
> My 3D objects disapeared after upgrading because the UserControl no longer
> streches its content.
> So you might assign a material to find out... That is the nice part about
> your implementation.
>
> BTW: Although your implementation is very creative I'd reccomend against it
> because of performance. Just calculating a Quaternion from two
> screencoordinates is much faster than doing a hit test.
>
> Erno
> ----
> WPF tutorials: http://blogs.infosupport.com/ernow/articles/1878.aspx
>
>
>
> "viliescu" <viliescu@discussions.microsoft.com> wrote in message
> news:38440214-4892-4DAB-99B3-E270594B0F16@microsoft.com...
> > In Dec CTP I was using a 3D sphere with no Material (Material = null) as a
> > trackball for my scene. I have ported the code to Feb CTP and it seems
> > that
> > the sphere is not hit anymore.
> > I just wanted to ask if this is a voluntary change and if it is the
> > intended
> > behaviour in the final version WPF and I should implement another
> > trackball
> > (probably the one from Daniel Lehenbauer).
> >
> > --
> > Valentin Iliescu [MVP C#]
>
>
>

Did you set HorizontalContentAlignment and VerticalContentAlignment of the
UserControl to "Stretch" ? (Are you using a UserControl?)

Erno

"viliescu" <viliescu@discussions.microsoft.com> wrote in message
news:2AB1A04B-0A2B-4537-9607-87F0E8F8368B@microsoft.com...
> Thanks Erno, I have tried to add a transparent material and/or set the
> opacity to 0 but it's not working - the objects from the sphere interior
> are
> not visible anymore.
> --
> Valentin Iliescu [MVP C#]
>
>
> "Erno" wrote:
>
>> Hi!
>>
>> My 3D objects disapeared after upgrading because the UserControl no
>> longer
>> streches its content.
>> So you might assign a material to find out... That is the nice part about
>> your implementation.
>>
>> BTW: Although your implementation is very creative I'd reccomend against
>> it
>> because of performance. Just calculating a Quaternion from two
>> screencoordinates is much faster than doing a hit test.
>>
>> Erno
>> ----
>> WPF tutorials: http://blogs.infosupport.com/ernow/articles/1878.aspx
>>
>>
>>
>> "viliescu" <viliescu@discussions.microsoft.com> wrote in message
>> news:38440214-4892-4DAB-99B3-E270594B0F16@microsoft.com...
>> > In Dec CTP I was using a 3D sphere with no Material (Material = null)
>> > as a
>> > trackball for my scene. I have ported the code to Feb CTP and it seems
>> > that
>> > the sphere is not hit anymore.
>> > I just wanted to ask if this is a voluntary change and if it is the
>> > intended
>> > behaviour in the final version WPF and I should implement another
>> > trackball
>> > (probably the one from Daniel Lehenbauer).
>> >
>> > --
>> > Valentin Iliescu [MVP C#]
>>
>>
>>

It is the intended behavior. A null Material property means the front faces
aren't being drawn thus there are no front faces to hit. We changed this
when we introduced BackMaterial.

You said you tried using a transparent Material... was it a DiffuseMaterial?
DiffuseMaterial writes to the depth buffer which will make things inside the
sphere disappear. Try a fully transparent EmissiveMaterial instead.

A virtual trackball like DanLehen's sample or as Erno suggests would be more
efficient.

Jordan

> In Dec CTP I was using a 3D sphere with no Material (Material = null) as a
> trackball for my scene. I have ported the code to Feb CTP and it seems
> that
> the sphere is not hit anymore.
> I just wanted to ask if this is a voluntary change and if it is the
> intended
> behaviour in the final version WPF and I should implement another
> trackball
> (probably the one from Daniel Lehenbauer).
>
> --
> Valentin Iliescu [MVP C#]

Thank you. I am going to change the trackball implementation, as suggested.
--
Valentin Iliescu [MVP C#]


"Jordan Parker [MSFT]" wrote:

> It is the intended behavior. A null Material property means the front faces
> aren't being drawn thus there are no front faces to hit. We changed this
> when we introduced BackMaterial.
>
> You said you tried using a transparent Material... was it a DiffuseMaterial?
> DiffuseMaterial writes to the depth buffer which will make things inside the
> sphere disappear. Try a fully transparent EmissiveMaterial instead.
>
> A virtual trackball like DanLehen's sample or as Erno suggests would be more
> efficient.
>
> Jordan
>
> > In Dec CTP I was using a 3D sphere with no Material (Material = null) as a
> > trackball for my scene. I have ported the code to Feb CTP and it seems
> > that
> > the sphere is not hit anymore.
> > I just wanted to ask if this is a voluntary change and if it is the
> > intended
> > behaviour in the final version WPF and I should implement another
> > trackball
> > (probably the one from Daniel Lehenbauer).
> >
> > --
> > Valentin Iliescu [MVP C#]
>
>
>